646331 ÷ 81 
We want to divide 646331 by 81.

Advancing to step 1:
6 divided by 81 is 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Bring next digit (4) of the dividend behind the 6 and repeat the process: 64 / 81

Advancing to step 2:
The number 81 fits into 64 0 times, leaving a remainder of 64.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 64 leaves us with 64.
Append the next digit (6) from the dividend to 64 and continue with: 646 / 81

Advancing to step 3:
81 goes into 646 7 times with a remainder of 79.
Put 7 as the next digit of the answer. 
Result so far: 7.0
Subtracting 567 from 646 leaves us with 79.
Bring next digit (3) of the dividend behind the 79 and repeat the process: 793 / 81

Advancing to step 4:
When dividing 793 by 81, we get 9 with a remainder of 64.
Record the quotient 9 as the next digit in the result. 
Result so far: 79.0
If we take 729 away from 793, we end up with 64.
Grab the next digit (3) from the dividend, add it to 64, then carry on: 643 / 81

Step 5:
If we divide 643 by 81, we get 7 and a remainder of 76.
Put 7 as the next digit of the answer. 
Result so far: 797.0
If we take 567 away from 643, we end up with 76.
Append the next digit (1) from the dividend to 76 and continue with: 761 / 81

On to step 6:
If we divide 761 by 81, we get 9 and a remainder of 32.
Use 9 as the next digit of our solution. 
Result so far: 7979.0
Deduct 729 from 761 and we're left with 32.
Since there are no more digits in the dividend, we add a zero to the remainder making it 320, and continue the process.

Advancing to step 7:
81 can be fit into 320 3 times, resulting in a remainder of 77.
The number 3 becomes the next digit in our result. 
Result so far: 7979.3
Subtracting 243 from 320 leaves us with 77.
Since there are no more digits in the dividend, we add a zero to the remainder making it 770, and continue the process.

On to step 8:
81 can be fit into 770 9 times, resulting in a remainder of 41.
Write down 9 as next digit of the result. 
Result so far: 7979.39
Subtract 729 from 770 to get 41.
Since there are no more digits in the dividend, we add a zero to the remainder making it 410, and continue the process.

Moving on to step 9:
The number 81 fits into 410 5 times, leaving a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 7979.395
The remainder is 5 after subtracting 405 from 410.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 10:
50 divided by 81 is 0 with a remainder of 50.
Write down 0 as next digit of the result. 
Result so far: 7979.395
Subtracting 0 from 50 leaves us with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Going ahead to step 11:
81 goes into 500 6 times with a remainder of 14.
Put 6 as the next digit of the answer. 
Result so far: 7979.39506
The remainder is 14 after subtracting 486 from 500.
Since there are no more digits in the dividend, we add a zero to the remainder making it 140, and continue the process.

Step 12:
When dividing 140 by 81, we get 1 with a remainder of 59.
Record the quotient 1 as the next digit in the result. 
Result so far: 7979.395061
Subtracting 81 from 140 leaves us with 59.
Since there are no more digits in the dividend, we add a zero to the remainder making it 590, and continue the process.

Let's proceed to step 13:
590 divided by 81 is 7 with a remainder of 23.
The next digit of our result is 7. 
Result so far: 7979.3950617
If we take 567 away from 590, we end up with 23.
Since there are no more digits in the dividend, we add a zero to the remainder making it 230, and continue the process.

Advancing to step 14:
230 divided by 81 is 2 with a remainder of 68.
Write down 2 as next digit of the result. 
Result so far: 7979.39506172
Subtracting 162 from 230 leaves us with 68.
Since there are no more digits in the dividend, we add a zero to the remainder making it 680, and continue the process.

In conclusion, the division gives 7979.39506172 with a balance of 6.8e-08.